FIELD OF APPLICATION
[0001] The current invention patent is a universal machine of rheological and mechanical
tests for modular tests of cementitious materials, such as mining, asphaltic, polymeric,
food, pharmaceutical, cosmetic materials, etc., with the aforementioned machine being
comprised of distinct modules that allow the investigation of mixture behavior, prediction
of fluid state characteristics and consolidation of inert or reactive heterogeneous
multiphase systems, with or without the presence of liquid phase and with elevated
granulometric extension.
TECHNICAL BACKGROUND
[0002] It is known that heterogeneous suspensions are characteristically composed of different
phases in their formulation, more explicitly, and can be the result of the combination
of liquids with solid particles, which can vary from millimeters to submicrons in
size. These suspensions also contemplate the combination of different immiscible fluids,
constituting emulsions in the system liquid phase, with the possibility of also including
air bubbles in the system.
[0003] These heterogeneous suspensions are present in different technological areas, such
as building materials as concretes, mortars, fibrocement, prefabricated components,
etc., soils, foods, cosmetic and mining products, etc.
[0004] One major difficulty involved with materials of such nature is related to the assessment
of the behavior of these materials in fluid state, even to those that will be transformed
into solids at some other processing stage.
[0005] The techniques for assessing the behavior of fluids in shear stress, known as rheological
characterization techniques, have as their basic principle the submission of these
fluids to controlled stresses or deformations. Countless methods described in the
literature are classified into four categories according to the flow measurement or
shear stress measurement procedure, which are:
[0006] Free flow tests - the material flows due to its own weight, without any confining,
or an object penetrates the material as the result of gravitational force;
Confined flow tests - the material flows due to its own weight or under the application
of pressure by means of a restricted orifice;
Vibration tests - the material flows due to the application of vibration;
Shear tests under rotational flow - the material is submitted to rotational shearing
in a parallel plate or concentric cylinders system
Another way of classifying the test methods is related to the shearing range in which
the materials being analyzed are submitted, given that in practice two major test
classes can be pointed: single point and multipoint.
[0007] The single point category encompasses the most of traditional tests employed in the
control of concretes consistency, as indicated in Table 1, besides the Vane test -
Amziane et al., 2005.
[0008] Table 1 contains the main methods for rheological characterization of fresh concrete,
based on the classification given by "Nist" - Koehler & FowlerKoehler & Fowler, 2003.
Table 1
NIST Classification |
Test |
Parameters |
Type of measurement |
Free flow |
Truncated cone |
Yield Strength |
single point |
Free flow |
Modified truncated cone |
Yield Strength; |
single point |
Confined Flow |
Orimet Test V-Funnel Test |
Viscosity |
single point |
Confined Flow |
Ability Filling |
Viscosity |
single point |
Vibration |
Powers Remolding Test |
Viscosity |
single point |
Rotational Rheometer |
Rheometers |
Yield Strength; Viscosity |
multipoint |
[0009] Generally speaking, these tests characterize the materials in a single strength or
shear rate condition. In the free and confined flow tests, the strength applied is
proportional to the density of the material, while in the vibration tests, the shear
rate applied is defined by the frequency and amplitude of the mobile element. In turn,
the Vane test is a test that quantifies the yield strength of compositions.
[0010] Results obtained by means of such methods do not provide, therefore, a complete rheological
characterization of concretes, with the possibility of resulting in wrong interpretations
about the behavior of concretes in fluid state, under different application conditions.
[0011] Illustrating this concept, the Figure 1 presents a schematic representation of three
distinct "Bingham" fluids. The schematic describes the strength vs. shear rate profiles
and the figures below the respective viscosities calculated as the ratio between strength
and shear rate.
[0012] Table 1 presents the main rheological characterization methods according to the "NIST"
classification, identifying the fundamental rheological parameters to which the test
is related. The aforementioned presents, still, a second form of classification of
these methods, based on the quantity of shear rates assessed during the single point
and multipoint tests.
[0013] As observed, the 'A' and 'B' systems present the same yield strength, but the strength
and fluid viscosity levels of 'B' are higher than those of system 'A' at the remaining
shear rates.
[0014] In Figure 1 it is verified the 'strength profiles' x 'shear rate', where the circles
in orange highlight the shear rates with the equivalent viscosities calculated as
the strength/shear rate ratio.
[0015] Besides the intrinsic uncertainties of the single point characterization concept,
the presented test methods do not isolate the fundamental rheological parameters,
with exception of the Vane test yield strength test. Overall, these methods provide
results that are influenced both by the viscosity as by the materials' yield strength,
as demonstrated in Figure 2 for determination of fluidity by means of the consistency
test similar to the truncated cone.
[0016] Finite element simulation results confirm that the consistency values present an
inversed relation with the two rheological constants, yield strength and viscosity.
[0017] As a matter of fact, the rheological assessment of reactive concentrated suspensions
with high viscosity, which consistency changes throughout time due to irreversible
microstructural changes, in other words, cement hydration, polymerization, coagulation,
etc., is a challenge in the field of rheology - Meeten, 2000.
[0018] Therefore, the identification of rheological parameters associated to the behavior
of fluids and suspensions must be made my means of multipoint techniques that assess
the behavior of materials at different shear rates and strengths, as in rheometry
tests - Pileggi et al., 2000.
[0019] Such multipoint tests consist of the rheological characterization of fluids and suspensions
in different conditions of shear strength and rate, enabling thus the simultaneous
identification of fundamental rheological parameters, in other words, yield strength,
viscosity and rheological profile. These types of tests applied to concretes are predominantly
based on rotational rheometry - Ferraris, 1999.
[0020] The aforementioned rheometers are pieces of equipment dedicated to the assessment
of rheological properties of fluids and suspensions, and allow the study of viscosity
and yield strength behaviors as a function of other variables, such as time, temperature,
etc.
[0021] The various rheometers for suspensions that are commercially available are based
on only two basic functioning principles - Stein, 1986, which are: (a) rheometer in
which the torque that is proportional to the strength applied to the fluid is controlled,
and the resulting shear is assessed; (b) rheometer in which the shearing applied to
the material is controlled, and the strength necessary for such is registered. Therefore,
it is verified that the torque rheometers are indicated to assessments in which the
strength requirements control the flow of material, while the shearing equipment are
the most indicated to assessments of the rheological behavior in various flow rates.
[0022] Overall, the commercially available precision rheometers are not adequate to materials
with an extensive granulometry, such as concretes and mortars, due to the fact that
these rheometers can only act in restricted torque ranges, being limited to systems
comprised of particles smaller than 100 µm.
[0023] Additionally, the commonly employed test geometries: concentric cylinders, parallel
plate, cone-plate, capillary, vane, etc., tend to not be adequate to the assessment
of concentrated systems or with addition of microparticles, which is the case of concrete
and mortars.
[0024] It is known that the first rheometer to be specifically developed to the rheological
characterization of concretes dates back to the 1960's, where the Powers model - Power,
1968 - was based on the concentric cylinders model for the application of shear forces
to the material. In this conception, the previously mixed concrete is poured into
a cylindrical container in which a rotational element, also cylindrical, is introduced
at the center of the mass, and the forces necessary the move the central cylinder
are registered.
[0025] Therefore, based on this architecture, new models have been developed, such as 'Wallevik'
and 'Gjorv' "Con Tec BML viscometer"; 'Coussot' "Cemagref-IMG"; 'Tattersall' and 'Bloomer'
"Two-Point rheometer" - Brower, 2001. Besides the aforementioned models, the technological
evolution of rheometers resulted in pieces of equipment that use other concepts for
sheared material, as the parallel plate system developed by Larrard et. al. "Btrheom"
and the planetary system proposed by 'Beaupré' "IBB rheometer" - Ferraris, 1999.
[0026] The rheometer for mortars and concretes developed at Poli-USP allows the use of two
concepts of shear application: concentration or planetary rotation.
[0027] The use of rheometers has gained space, and the paper published in 1998 by the National
Institute of Standards and Technology - NIST - 'Ferraris and Larrard, 1998' can be
highlighted among several others. In this paper, following a bibliographic review
about the rheological characterization of construction concrete, it is proposed the
use of rheometers for the characterization of high-performance self-yielding concretes.
[0028] The importance of using rheometers in the rheological characterization of concretes
has been recognized in such manner that in September 2001, NIST published a report
related to an international cooperation work carried out between eight countries,
called 'Comparison of concrete rheometers': International tests at LCPC - Nantes,
France, 2000 - Ferraris & Brower, 2001.
[0029] The main purpose of this project consists in comparing, for the first time, the operational
performance of distinct rheometers 'Con Tec BML viscometer', 'Cemagref-IMG', 'Two-Point
rheometer', 'Btrheom e IBB rheometer', given that, there were no standards and norms
for the functioning of such pieces of equipment at the time.
[0030] Therefore, the five rheometers were transported from their countries of origin for
the Laboratoire central des ponts et chaussées (LCPC) in France, being simultaneously
used in the assessment of the behavior of several concrete compositions.
[0031] Among the observations contained in the report, the main one was the confirmation
that, in spite of the absolute differences between the measured values, the rheometer
assess and classify in a similar manner the rheological behavior of distinct concretes,
as observed by the yield strength and viscosity in Figure 3, which provides the conditions
for a future establishment of correlation curves between the devices.
[0032] In spite of the advantages associated to rheometry, the large dimensions of rheometers
of concretes do not allow the portability that is necessary for their use in technological
control in construction works, being, therefore, indicated for the development of
compositions in laboratories and concrete centers.
[0033] This technology gap has been overcome with the arrival of portable rheometers, which
consist of simplified, solely dedicated to the execution of standardized control tests
in construction works.
[0034] One additional advantage of the use of rheometers for the characterization of concretes
comes from the fact that the identification of its parameters and rheological profiles
(see schematic example in Figure 1), in different shear requests, occurs in a simultaneous
manner. Therefore, one only rheometry test provides subsidies for defining the adequation
of compositions to the proposed application methods.
[0035] The use of rheometers has enabled a better comprehension of factors that affect the
behavior of cementitious materials. Figure 4 presents the example of one schematic
based on the paper by 'Banfil 2005', on the impact of different contents of water,
air, microsilica (ultrafine particles) and dispersant on the viscosity and the mortars
yield strength.
[0036] As observed, the increase of water and dispersant, represented by the sense of arrows,
result in the decrease of both rheological parameters. However, the increase in air
content practically does not affect the yield strength, in spite of a large impact
on viscosity. At last, the increase in microsilica content reduces the viscosity,
but it increases the yield.
[0037] The use of the rheometry technique allows a detailed comprehension of the impact
that each of the components has on the behavior of concretes in fresh state. Therefore,
this characterization tool is fundamental for the preparation of a formulation methodology
based on microstructural/rheological concepts.
[0038] However, all the pieces of equipment describe present some limitations, such as the
rheometers 'Com Tec BML viscometer', 'Cemagref- IMG', 'Two-Point rheometer', 'Btrheom',
'IBB rheometer', portable rheometer and 'Icar' rheometer dedicated to a single family
of tests, being comprised of a single set of container and shear geometry.
[0039] Another drawback is due to the fact that the mobile rheometers are not rigid, resulting
in inaccurate measurements.
[0040] Another drawback is due to the fact that the existing rheometers do not have a system
for compensating segregation, and, therefore, they do not allow the execution of long-term
tests.
[0041] Another drawback is due to the fact that commercially available rheometers are developed
for the assessment of concretes with fluid consistency or mortars that are not plastic.
[0042] Another drawback is due to the fact that the existing rheometers do not have a system
for compensating segregation, and, therefore, they do not allow the execution of long-term
tests.
[0043] Another drawback is due to the fact that commercially available rheometers are developed
for the assessment of concretes with fluid consistency or mortars that are not plastic.
[0044] Another drawback is due to the fact that the existing pieces of equipment do not
act in concretes that require high levels of torque, as dry materials.
[0045] Another drawback is due to the fact that the commercially available pieces of equipment
are not able to mix materials.
[0046] Another drawback is due to the fact that conventional rheometers do not allow the
adaptation of devices for mechanical tests.
STATE OF THE ART ANALYSIS
[0047] In a research made in specialized databases, some documents related to rheometers
were found, such as the document no. PI 0107975-1, which is about methods for studying
the properties of a fluid and for producing an extruded polymer, revealing a device
for studying the properties of a fluid, polymer production plan, method and device
for monitoring one transition from a first product specification to a second product
specification in a polymerization process, and, polymer product.
[0048] In this state of the art document, one rheometry method and its corresponding device,
with the particular application of polymer manufacturing, are revealed.
[0049] This method is performed with the purpose of studying the properties of a polymer
by means of a rheometer, with a pump and an array disposed in a way that the polymer
is pumped through the array with the aid of transducers that measure pressures inside
the rheometer.
[0050] In this method, the polymer is supplied to the rheometer, and the pump is set at
a speed and value(s) that are indicative of the shear strength in the fluid inside
the array, obtained by means of transducers that provide data.
[0051] The pieces of data are then directly compared, with the use of multivariate analysis
with the data previously obtained, which correspond to polymer(s) with known rheological
properties.
[0052] The results of this comparison can then be used for controlling the manufacturing
process.
[0053] The document no. PI 9907518-0 refers to a polymeric material morphology visualization
device for rotational rheometers, in which the system allows the visualization of
the morphology evolution of immiscible polymer blends, or fiber-reinforced polymers,
submitted to shear flows in the linear viscoelasticity or nonlinear viscoelasticity
regime.
[0054] This piece of equipment is comprised of a lighting system, with one mercury vapor
lamp which beam is collimated by a set of lenses and deviated by a mirror so as to
focus on the sample.
[0055] This piece of equipment also includes a morphology visualization system, with one
mirror placed under the bottom shearing element of a camera with microscopic lens
that allows up to 1000x magnification, enough to visualize morphology to which the
size of the disperse phase is coupled to a digitalization device in a microcomputer.
[0056] During the polymer deformation test the light beam is transmitted through the sample
following the optical path.
[0057] The system allows the visualization of the morphology evolution of immiscible polymer
blends, or reinforced polymers during shear flows known in the linear viscoelasticity
or nonlinear viscoelasticity, just as the verification of non deformation of the morphology
of blends submitted to flows that correspond to linear viscoelasticity.
[0058] Another document numbered PI9816066-4 reveals one rheometer of double winding extension,
which comprises one transmission shaft, connected to an enclosure, where the enclosure
is additionally connected to a torque shaft, and two rotating drums are mounted onto
the enclosure.
[0059] The ends of a sample are connected to each drum and the drums are rotated, stretching
the sample until it breaks. The torque on the equipment caused by the stretching of
the sample is measured. The environmental control can be produced for testing samples
under different conditions.
PURPOSES OF THE INVENTION
[0060] With the purpose of presenting improvements to the consumers market, the applicant
has developed a universal machine for rheological and mechanical tests for modular
tests of cementitious materials, such as mining, asphaltic and polymeric materials,
foods, pharmaceutical products, cosmetics, etc.
[0061] The aforementioned machine adopts concepts of speed and rotation direction control,
torque control and especial modular architecture that are combined in order to comprise
a universal machine for rheological and mechanical tests for the assessment of rotational
shear forces, as well as the inclusion of a load cell optional device for recording
longitudinal forces perpendicular to the rotation direction.
[0062] The modular architecture is basically comprised of:
- a) Organizational structure made in aluminum and hard steel, free from vibrations
and torsion during tests, essentially comprised of a base provided with fastening
points and four anti-vibration stands and at least one pan lock, as well as one support
to the pan. This base also has a platform elevator, which slides in guide columns
attached to the base, with the opposite ends of each guide column equipped with fastening
members of an upper lock.
- b) Electronic system housed in an electronic components cabinet;
- c) Dry gear reducer without oil lubrication;
- d) Alternate current servomotor;
- e) Fast coupling system for changing geometries and test containers;
- f) Set of distinct shear elements with variable geometries for the execution of rheological
tests;
- g) Fast coupling system able to withstand devices for the performance of mechanical
tests with hardened materials;
- h) Test containers with different geometries and volumetric capacities;
- i) Transportation system of equipment and test containers;
- j) Electronic system for speed control, torque control and rotation direction;
- k) Load cell device for recording regular longitudinal forces;
- l) Modular test software for speed control, torque control and rotation direction;
- m) Result analysis software;
- n) Electronic system and software for submitting test results for remote analysis;
- o) System for the acquisition of ambient temperature and temperature at the test container.
[0063] Such configuration allows the assessment of particulate materials in dry conditions,
identifying properties as friction between particles, compaction capacity, presence
of moisture, etc., as well as systems with the presence of liquid phase, both pure
and combined in emulsion and suspension forms, being able to assess since the component
mixing and combination to the consolidation of these systems in case of reactive materials.
[0064] As it assesses the rotational shear behavior, the rheometer is also able to analyze
the rheological behavior in any system that is being sheared.
[0065] Therefore, the main advantage of the innovative machine is the junction of two distinct
modules that allow different combinations of accessories and software in order to
comprise the assessment of rotational shear forces of suspensions and granular material
with a wide range of granulometry and consistencies, rendering the machine completely
customizable to different families of materials and applications.
[0066] Another advantage is due to the fact that the execution of mechanical tests in combination
with rheological tests provides a degree of originality that is not found in equipment
for high torque tests. Therefore, it is now possible to infer that the current invention
extends the concept of rheological tests in heterogeneous multiphase suspensions to
a range of tests that had never been previously performed, even including the possibility
of combining mechanical to rheological tests.
[0067] Another advantage is due to the fact that the provision of a fast-action type coupling
system allows the installation of different accessories, being possible to mount mechanical
claws for supporting and assessing materials in hardened state.
[0068] Another advantage is due to the fact that the machine allows the dry assessment of
particulate materials, identifying properties such as friction between particles,
acting as a tribometer; assessing the compaction capacity with or without moisture,
in systems that have liquid phase, both pure and combined in emulsion and suspension
forms, able to assess since the component mixture and combination stage up to the
consolidation of these systems in case of reactive materials.
[0069] Another advantage is due to the fact that the modular architecture of the universal
machine allows its use in different segments, such as in the area of cementitious
materials as cement, concretes, mortars, as well as mining, asphaltic and polymeric
materials, foods, pharmaceutical products, cosmetics, etc.
[0070] Another advantage is due to the fact that the constructiveness of the universal machine
ensures its mobility, also encouraged by the provision of use in combination with
a transportation device (utility cart) that can carry the machine and be used for
the collection of test material, given that the base predicts a fast coupling system
of test pans, reducing the effort of moving test containers, especially at locations
that are far from the equipment, considering that the estimate weight of recipients
supplied with material reaches 60 kg.
[0071] Therefore, the use of a utility cart gives mobility to the machine, practicality
for the collection of samples, and it also reduces the work efforts by operators,
avoiding issues of hazards to operators caused by handling heavy loads.
[0072] Another advantage is due to the fact that the constructive characteristics of the
machine allow the torque control and possibility of oscillation during tests, as the
result of the rotation direction control, as well as it controls the actuation of
the linear actuator for the positioning of the elevating mobile platform during tests.
[0073] Another advantage is due to the fact that the full sealing of the universal machine
allows its use in aggressive environments in terms of dirty conditions, restricting
the ingress of dust particles, besides allowing the equipment to be easily washed
with water.
DESCRIPTION OF FIGURES
[0074] In order to complement the current description for a better comprehension of characteristics
of this invention, and according to a preferable practical execution of this invention,
this description is followed by a set of drawings which represents in an exemplified
and non limitative manner its functioning:
Figure 1 represents a schematic illustration of the rheological behavior of three
distinct Bingham fluids;
Figure 2 reveals a graph of the relation between the fluidity value and the rheological
constants: yield strength (Ty) and viscosity (η);
Figure 3 shows a graph of the yield strength (a) and viscosity (b) of compositions
tested in the comparative study of rheometers;
Figure 4 illustrates a graph based on 'Viskomat NT' rotational rheometry results,
related to the impact of different contents of water, air, microsilica - ultrafine
particles - and dispersant on the vis and yield strength of mortars. The arrows indicate
increases in parameters - Banfill, 2005;
Figure 5 represents an exploded view of elements which makes up the innovated rheometer;
Figure 6 shows an exploded view of the gear reducer assembly;
Figure 7 illustrates an assembled view of the gear reducer assembly;
Figure 8 reveals an assembled view of the innovated rheometer;
Figure 9 shows a front view;
Figure 10 shows a side view;
Figure 11 represents a front view of electric control panel;
Figure 12 illustrates a perspective view of the coupled rheometer on the utility cart;
Figure 13 shows a perspective view of the utility cart transporting the test container;
and
Figure 14 illustrates schematic views of different test geometries.
DETAILED DESCRIPTION OF THE INVENTION
[0075] In reference to the illustrated drawings, the current invention patent refers to
the "UNIVERSAL MACHINE OR RHEOLOGICAL AND MECHANICAL TESTS", which is, more precisely,
an universal machine (1) of rheological and mechanical tests for modular tests of
cementitious materials, as well as mining, asphaltic and polymeric materials, foods,
pharmaceutical products, cosmetics, etc.
[0076] According to the current invention, the universal machine (1) comprises the arrangement
of a set of modules (CM) that make up means of rheological and mechanical tests for
the assessment of rotational shear forces, as well as recording of longitudinal forces
perpendicular to the rotation direction of the gear reducer assembly (50), considering
that these modules (CM) are comprised of: a) structural organization (2); b) electronic
components cabinet (3) of the electronics system (St)/(Sw); c) dry gear reducer (4);
(d) alternate current servomotor (5); e) fast coupling system (Eg) for changing geometries
(18); f) test containers (8), as well as devices for the execution of mechanical tests
with hardened materials; g) load cell type device for recording the regular longitudinal
forces.
[0077] The aforementioned machine (1) provides the interconnection with a data processing
system (PC) and the aforementioned modules (CM) are controlled by a specific electronic
system (St) for speed control, torque control and rotation direction. This electronic
system (St) is comprised of specific subassemblies, which are:
- Servoconverter (St1), preferably the model SCA06, manufactured by WEG, compatible
with the gear reducer assembly (50) used;
- Electric components (St2) for supplying electric current and protection against sudden
voltage variations of the servoconverter (St1) that controls the alternate current
servomotor (5) and the linear actuator (11) that moves elevating mobile platform (2A)
provided for the structural organization (2);
- Electronic components (St3) for control and acquisition of movement data of the alternate
current servomotor (5) and linear actuator (11);
- Electric control panel (10) installed inside the electronic components cabinet (3),
to be provided with an on-off switch (10a), error indicator light (10b) on the servoconverter,
emergency shutdown switch (10c), USB connection (10d) and energy supply to the control
computer (PC), manual control switch (10e) for controlling the vertical motion of
the elevating mobile platform (2A);
- Optional Wi-Fi communication system (St4) between the computer (PC) and the electronic
components cabinet (3);
- Modular control, data acquisition and results analysis software (Sw) for programming
the rotation to be used during tests simultaneously to the motion of the elevating
mobile platform (2A) and the acquisition of torque forces that result from tests.
The aforementioned software (Sw) provides:
- i) modular test control system (Sw1) for speed control, torque control and rotation
direction of the alternate current servomotor (5);
- ii) data acquisition system (Sw2) for recording in real time all responses provided
by the gear reducer assembly (50), besides controlling the time and temperature measurement
system, generating data in exportable format for conventional analysis software, such
as Excel, as well as for the results analysis software (Sw3);
- iii) results analysis system (Sw3) in which the data recorded by the data acquisition
system (Sw2) is analyzed by an exclusive rheological analysis software;
- iv) remote data transmission system (Sw4) that works in parallel to the other systems
for sending data from testing locations to computers located in specific locations;
- v) complementary systems (Sw5) that can be coupled to the machine (1) and, consequently
increase the scope and effectiveness during the service.
[0078] In the ideal constructive version, the complementary system (Sw5) presents:
- Defined location (Sw5') for the installation of a load cell at the supporting base
(2B) of the test container (8) for recording the regular longitudinal forces during
tests;
- Temperature acquisition system (Sw5") for acquisition of temperature at four different
positions: position on the gear reducer assembly (50); position on the electronic
components cabinet (3) of the electronics system (St)/(Sw); position on the environment;
position on the test container (8).
- Mechanical testing systems (Sw5") for materials in hardened state. The structural
rigidity of the machine (1) allows the execution of mechanical tests in devices to
be coupled to the center shaft of the planetary system and to the fast coupling system
(Eg) of the die cast base. Therefore, various testing systems can be conceived for
the execution of tests where the vertical motion of the elevating mobile platform
(2A) generates vertical forces to be recorded by the load cell.
[0079] In an ideal constructive version, the structural organization (2) is preferably made
of aluminum and hard steel or other suitable material, being comprised of three main
subassemblies, which are: base (2B), elevating mobile platform (2A) and locking element
(2C) of the assembly. The aforementioned base (2B) (see Figure 5A) is ribbed and has
weight relief holes; the transversal section in "U" shape makes up sidewalls (2d)
where orifices (2e) were made for fitting guide columns (2f) and sliding the elevating
mobile platform (2A), which has its vertical motion made by the linear actuator (11)
installed between the base (2B) and the elevating mobile platform (2A).
[0080] The interior surface of the base (2B) provides means of coupling a set of anti-vibration
stands (12), while the opposite surface receives a supporting plate (13) for the test
container (8).
[0081] Each side wall (2d) of the base (2) features some cutouts (2g) in order to serve
as handles (AL) for transporting the machine (1).
[0082] The aforementioned support plate (13) provides a central cutout (13a) for the connection
of the fast coupling (Eg) of the container (8) base (2B), and this fast coupling (Eg),
made of steel and comprised of a lever (6a) formed by an inverted "L"-shaped tubular
profile part, which has its free end (6b) coupled to an orifice of the supporting
member (2H) to be provided on this base. The 90° motion of the lever (6a) promotes
the release of the container (8) from the support plate (13).
[0083] The aforementioned elevating mobile platform (2A) is comprised of a single ribbed
part (2i) provided with weight relief holes where the peripheral area of the elevating
mobile platform (2A) corresponds to the base area (2B), provided with four extreme
cylindrical members (2j) where a pair of linear bearings (14) is mounted, ensuring
the vertical sliding of the platform (2A) on the guide columns (2f). These bearings
(14) are fastened by elastic rings (15) and an Allen headless screw.
[0084] The vertical motion of the elevating mobile platform (2A) on the columns (2f) is
obtained by the linear actuator (11) with positioning control made by Hall sensor,
commanded by means of an electronic system (St) and software (Sw).
[0085] The gear reducer assembly (50) is armored and assembled in a position aligned with
the vertical shaft (E1) in a center bore (21) on the base of the elevating mobile
platform (2A); the aforementioned gear reducer assembly (50) receives a protection
cover (16) and it can be divided into three parts, which are: alternate current servomotor
(5), cycloidal gear reducer (4) and planetary gear reducer (7). The alternate current
servomotor (5) is supplied with 200V supply voltage, features 7.0 Nm of torque and
maximum rotation speed of 3000 rpm, and it provides an electromagnetic brake that
is directly coupled to the gear reducer, which, in turn, does not need oil lubrication,
as it is comprised of a primary cycloidal reducer (4) with an eccentric bearing coupled
to a secondary planetary reducer (7).
[0086] The aforementioned secondary planetary reducer (7) provides a center shaft with fast
coupling system for changing testing geometries (18), besides a fast coupling system
able to support devices for the execution of mechanical tests with hardened materials.
[0087] These geometries (18) are, preferably made of stainless steel and can present various
formats (see Figure 14), such as, finned geometry for the 200 mm container, finned
geometry for the 400 mm container, parallel plates and DIN fin.
[0088] The test containers (8) can present different geometries and volumetric capacities,
made of stainless steel and "U"-shaped section which has an ring-shaped handle (8a)
in the edge that assists in the transportation, while at the base (8b) there three
short cylindrical projections (8c) that assists in the positioning and locking in
cutouts (13a) provided to the aforementioned plate (13).
[0089] The dimension variation of containers (8) can be the following: 400 mm of inside
diameter and 200 mm of height and another model with 200 mm of inside diameter and
200 mm of height, where the choice of containers (8) is related to the size of the
largest particle to be tested, with 6 mm for the smaller container and 20 mm for the
larger container.
[0090] The aforementioned machine (1) is provided with an utility cart (17) so that it can
be manually transported to the work place. This cart (17) is comprised of a platform
(17a) with projecting arms (17b). This platform (17a) is provided with a pair of wheels
(rd), which are mounted on stands (17c). The free ends of these stands are developed
into handles (17d) that allow the cart (17) to be guided for the transportation of
the machine (1) or containers (8).
[0091] Therefore, the constructiveness of the machine, combined with the operational (St)
and software (Sw) ensure the simplified operation, which functioning can be divided
into the second stages:
- a) Transportation and assembly of the machine (1) by means of the utility cart (17)
for the test location, which can be a laboratory or at the location of application
of concrete, mortar, etc. At the location, the machine (1) must be connected to a
three-phase electric power supply, 220 V;
- b) The utility cart (17) can then be uncoupled in order to be used for collecting
materials at the location of their production, for subsequent analysis by the machine
(1);
- c) Activation of the machine (1) as the electric power supply is connected. The first
task consists in connecting the control computer (PC) by means of the USB connection
at the upper part of the electric panel (10). From this moment, the machine (1) can
be turned on at the on/off switch (10a), and the computer can be started right after.
- d) The control of the machine (1) is performed by means of the software (Sw); and
- e) Collection of material and test execution tasks are performed by moving the test
container (8) up to the point of collection of concrete material, mortar, etc. at
the location of production and return to the machine (1) for the execution of tests.
After the container (8) is placed on the base (2B) of the machine (1), the defined
test geometry (18) is coupled and the test is started by means of the control software
(Sw).
[0092] Another alternative for performing the test consists in placing the container (8)
and test geometry (18) on the machine (1), adding the materials to be tested to the
container. That can be done by placing the anhydrous materials so that they can be
mixed in the machine (1) or placing the ready material only for analysis at the equipment.
[0093] Once tests are completed, the machine software (1) will generate electronic results
files that are analyzed by another software specifically developed for handling torque,
rotation, time and regular force data. The analysis software provides rheological
information from tests and compares results obtained in different tests, besides allowing
the assessment of results' compliance with previously defined behavioral standards.
It is certain that when this invention is put into operation, certain modifications
can be introduced in regards to certain construction and form details, without interfering
with the fundamental principles that are clearly substantiated in the context of the
claim, thus, being understood that the terminology used was not intended to be limited.
1. Universal machine for rheological and mechanical tests, is, more precisely, an universal
machine (1) for rheological and mechanical tests, for modular tests of cementitious
materials, as well as mining, asphaltic and polymeric materials, foods, pharmaceutical
products and cosmetics, etc.;
characterized as being the universal machine (1) comprised of the arrangement of a set of modules
(CM) that make up means of rheological and mechanical tests for the assessment of
rotational shear forces, as well as the recording of longitudinal forces perpendicular
to the rotation direction of the gear reducer assembly (50), with the aforementioned
modules (CM) comprised of: a) structural organization (2); b) electronic components
cabinet (3) of the electronics system (St)/(Sw); c) dry gear reducer (Eg) for changing
geometries (18); f) test containers (8) and devices for performing mechanical tests
with hardened materials; g) load cell device for recording regular longitudinal forces;
the aforementioned machine (1) provides the interconnection with a data processing
center (PC) and its modules are controlled by a specific electronic system (St) for
the speed control, torque control and rotation direction, which is comprised of specific
subassemblies, which are:
- servoconverter (St1) compatible with the alternate current servomotor (5) used;
- electric components (St2) for the supply of electric current and protection against
sudden voltage variations of the servoconverter (St1) that controls the alternate
current servomotor (5) and linear actuator (11) that moves the elevating mobile platform
(2A) provided in the structural organization (2);
- electronic components (St3) for the control and data acquisition of the alternate
current servomotor (5) and linear actuator (11);
- electric control panel (10) installed in the electronic components cabinet (3) where
are to be provided one on-off switch (10a), error indicator light (10b) on the servoconverter
(St1), emergency shutdown switch (10c), USB connection (10d) and power supply to the
control computer (PC), manual control switch (10e) of vertical motion of the elevating
mobile platform (2A);
- optional Wi-Fi communication system between the computer (PC) and the electronic
components cabinet (3);
- modular software of control, data acquisition and result analysis (Sw) for the programming
of rotation to be employed in tests, simultaneously to the motion of the elevating
mobile platform (2A) and acquisition of torque forces resulting from tests. The aforementioned
software (Sw) provides: i) modular control system of tests (Sw1) for the speed control,
torque control and rotation direction of the alternate current servomotor (5); ii)
data acquisition system (Sw2) for recording in real time all the responses provided
by the alternate current servomotor (5), besides controlling time and the temperature
measurement system, generating data in exportable format to conventional analysis
software, such as the result analysis software (Sw3); iii) result analysis system
(Sw3) in which the data recorded by the data acquisition system (Sw2) is analyzed
by an exclusive rheological analysis software; iv) remote data transmission system
(Sw4) that acts in parallel to the other systems for submitting data from test locations
to computers located in specific locations; v) complementary systems (Sw5) that can
be coupled to the machine (1).
2. Universal machine for rheological and mechanical tests, according to claim 1 and in
an ideal constructive version,
characterized as being the complementary system (Sw5) comprised of:
- a defined location (Sw5') for the installation a load cell on the support base (2B)
of the test container (8) for recording the regular longitudinal forces during tests;
- a temperature acquisition system (Sw5") for the acquisition of temperature at four
different positions: which are: position on the alternate current servomotor (5);
position on the electronic components cabinet (3); position on the environment; position
on the test container (8), and
- mechanical test systems (Sw5") for materials in hardened conditions, as the machine's
(1) structural rigidity allows the execution of mechanical tests on devices to be
coupled on the center shaft of the planetary gear reducer and on the fast coupling
system (Eg) of the die cast base.
3. Universal machine for rheological and mechanical tests, according to claim 1 and in
an ideal constructive version, characterized as being the structural organization (2) manufactured in aluminum and hard steel,
comprised of three main subassemblies, which are: base (2B), elevating mobile platform
(2A) and locking element (2C) of the assembly; the aforementioned base (2B is ribbed
and features weight relief holes, the transversal section in "U" shape makes up sidewalls
(2d) where orifices (2e) were made for fitting guide columns (2f) and sliding the
elevating mobile platform (2A), which has its vertical motion made by the linear actuator
(11) installed between the base (2B) and the elevating mobile platform (2A); the lower
surface of the base (2B) provides coupling means of a set of anti-vibration stands
(12), while the opposite surface receives a support plate (13) of the test container
(8); each side wall (2d) of the base (2B) features some cutouts (2g) in order to serve
as handles (AL) for transporting the machine (1); the aforementioned support plate
(13) provides a central cutout (13a) for the connection of the fast coupling (Eg)
of the container (8) base (8b), and this fast coupling (Eg), made of steel and comprised
of a lever (6a) formed by an inverted "L"-shaped tubular profile part, which has its
free end (6b) coupled to an orifice of the supporting member (2h) to be provided on
this base. The 90° motion of the lever (6a) promotes the release of the container
(8) from the support plate (13); the aforementioned elevating mobile platform (2A)
comprises a single ribbed part (2i) provided with weight relief holes, where the peripheral
area of the elevating mobile platform (2A) corresponds to the base area (2B), provided
with four extreme cylindrical members (2j) where a pair of linear bearings (14) is
mounted, ensuring the vertical sliding of the platform (2A) on the guide columns (2f).
These bearings (14) are fastened by elastic rings (15) and an Allen headless screw.
4. Universal machine for rheological and mechanical tests, according to claim 1,
characterized as being the armored gear reducer assembly (50) assembled in a position aligned with
the vertical shaft (E1) in a center bore (21) on the base of the elevating mobile
platform (2A); the aforementioned gear reducer assembly (50) receives a protection
cover (16) and it can be divided into three parts, which are:
alternate current servomotor (5), cycloidal gear reducer (4) and planetary gear reducer
(7); the alternate current servomotor (5) is supplied with 200V supply voltage, features
7.0 Nm of torque and maximum rotation speed of 3000 rpm, and it provides an electromagnetic
brake that is directly coupled to the gear reducer, which, in turn, does not need
oil lubrication, as it is comprised of a primary cycloidal reducer (4) with an eccentric
bearing coupled to a secondary planetary reducer (7); the aforementioned secondary
planetary reducer (7) provides a center shaft with fast coupling system for changing
testing geometries (18), besides a fast coupling system able to support devices for
the execution of mechanical tests with hardened materials.
5. Universal machine for rheological and mechanical tests, according to claim 1, characterized as being the geometries (18) made in stainless steel that can present various formats,
such as finned geometry for the 200 mm container, finned geometry for the 400 mm container,
parallel plates and DIN fin.
6. Universal machine for rheological and mechanical tests, according to claim 1, characterized as being the test containers (8) made of stainless steel and "U"-shaped section which
has an ring-shaped handle (8a) in the edge that assists in the transportation, while
at the base (8b) there three short cylindrical projections (8c) that assists in the
positioning and locking in cutouts (13a) provided to the aforementioned plate (13);
the dimension variation of containers (8) can be the following: 400 mm of inside diameter
and 200 mm of height and another model with 200 mm of inside diameter and 200 mm of
height, where the choice of containers (8) is related to the size of the largest particle
to be tested, with 6 mm for the smaller container and 20 mm for the larger container
7. Universal machine for rheological and mechanical tests, according to claim 1, characterized as being the utility cart (17) comprised of a platform (17a) with projecting arms
(17b). This platform (17a) is provided with a pair of wheels (rd), which are mounted
on stands (17c). The free ends of these stands are developed into handles (17d) that
allow the cart (17) to be guided for the transportation of the machine (1) or containers
(8).